Pluripotent stem cells, such as human embryonic stem (ES) cells (Non Patent Literature 1) and induced pluripotent stem (iPS) cells (Non Patent Literature 2), are cells proliferating infinitely and differentiating into various cell types, and thus are expected as a material for regenerative medicine. However, since the transplantation of a cell specimen containing a small amount of undifferentiated cells resulted in teratomas in an animal model, concern over its safety has been raised. Thus, it is necessary to remove such undifferentiated cells, that is, cells that are pluripotent.
To detect such human pluripotent stem cells, an antibody to SSEA-4 (stage-specific embryonic antigen 4) has been widely used (Non Patent Literature 3). To remove pluripotent cells from a cell population using SSEA-4 as an index, it is necessary to perform sorting with a flow cytometer or the like using the antibody to SSEA-4. At this time, since the antibody is used, there is concern that the transplantation material is contaminated with the antibody; thus, there is need for a method for selectively removing pluripotent cells by another method.